Reducing mill



4 Sheets-Sheet l 8 Nu mw H. c. INZSLEE REDUCING MILL Filea Nov. 19, 1943 Ott. 16,, 1945.

H. C. INSLEE Oct. 16, 1945.

REDUCING MILL Filed NOV. 19, 1943 4 Sheets-Sheet 2 INVENTOR.

Oct. 16, 1945. Q [NSLEE 2,386,863

- REDUCING MILL Filed Nov. 19, 1343 4 Sheets-Sheet 3 FT I I 1 :j- 1

IN VEN TOR.

Oct. 16, 1945.

H. C. INSLEE REDUCING MILL Filed NOV. 19, 1943 mil" 4 Sheets-Sheet 4 BY (gi/VENTOR.

HTTOIPNE'Y Patented Oct. 16, 1945 REDUCING Haber Culnslee East Orange, N. J., assignor, by,

mesnetassignments, to Rockrite Processes, Ino., Stamford; .Conn.,- a .corporation of Delaware Application-November-19, 1943,;Serial No;-510,879w

13,Claims.- (CI. 8014) v This invention relates :toreducing mills for must,.therefore,rbewunder'z'contnol of -asuitable reducing metal tubes antibar-s; and more-parties driving i'mechanism, j,and,:being;;under-, control of ularly'to'step by steplreducing millsof the pil'ger th driving; mechanism,:,the"speed'at which :the" type; that is; mills-"=in--w-hich* the workpiece recip workpiece:is-drivenfduring thatt par-tr of thework rocates between"gappeel -die--rol1s-whi'ch rotate 5 ingostroke-in which :the rollsaroma-enga en continuously in one direction aboutfixedaxes, the with the workpiece: mustbmmaintained-appmxh die-roll's reducing the-workpieceaduring its suc-. mate'ly eq-ualito the -pitch1uline speed of-:'the'diecessive-strokes-in one-direction and'leaving it free grooves: rlii1-ing it5-= non workihg return stroke and the The'ohjeets-oi-'the'present invention is; =there-' workpiece being given an' increment of feed and 110 foregitoavoid-theseshocks:andntoiprovide a rew a partial"turn -for-- each complete reciprocation, cineinga-milltwhich:when :used for coldworking and to amill of this type-in which the reciprocatbee-operated atzicompar-atively -high'.-speeds. ing movements "of the workpiece; and also oil-then Tothis-end, theeinventionicomprises an improved mandrel in a tubereducin mill, are. unclerucon: driving mechanismawhereby-ttherworkpieee;- and tr'ol' of positively-operated"driving means other ,15 jme mandreleinna tuberreducing mill :are than the rolls during both the. working anclire-- driveniat a uniformspeedwhiciris-sapproximately turnstrokesi the =pit chline speeds-oft the adie-zgrooves 1 of :the

The invention" hasrbeen made .wespecially for rollsduring a majoreportioneof bothvtherwork the purpose of'--providing--an improveclimillifor ing anziireturn strokes fland their: movement 1 reducing metal tubes :in'the cold-,state,-.obut .millsQ reversed-betweenithe-rstrokes=-mthzasymmetrical according to the invention may belusedialsou-fordecelerationandacceleration,and-wherebyatthe hot reductionoftubes, and ,featuresofhthejnbeginning ofseachiworkin-gistrokeather-speed-ofventionare adapted 'forbothhot ,andacoldlree theworkpieceriis,;brought:up tooapproximate y duction-of bars and rods". v the;{pitch linerspeedaoft-the:dieagrooves before" The efiiciency and capacity of. pilgerln-ills dethe workpieceis-engaged bythe rollsvz Thetoper-apend primarily on theoperati'ng speediof which tioneofv:thet-millhis therefore, such-athat --shock-. y a e pable without, impairment. of smooth from ..impact:of thesdies.- onwthe fworkpieee and a operation. In the conventionaljpilgermills used: from sudden,.-stoppag of reciprocating:,-parts atfor hot Working, the workpieceris moved on the: the.-end:rofqtheistrokesein either direction Jar-e working stroke by'the die rolls against the implies-1 V 3 substantially eliminated. Furthermore, due to sureof a springer, a fluid-pressed piston, and, the. decelerating oandoaccelerating-r movements when theworkpie'ce is .free. fromtthe rollsv atmthe. beingsymmetricahthe-inertia effects at theend end of the working stroke itsis givLenits return of .-strol ey.can ,be balanced by suitable countermovement by t e p ngprfihidpressed.,piston, balancing means. This is rot-special:importance and at the beginning ofteachiworkingstrokethm intcompar-atively 1arge and;heavy mills.

rolls grip. the workpiece while -it. .is;-;stationary. InHa mi-llhavingvthe new drivin ec There is; therefore, a considerable; shockron the 1 the workpiece, another-mandrel in\,-a;-,tube. reimpactv of" the the rolls. on therstationarv work-admcingmill,,aredriven'ataruniformsspeedwhich piece, a d j ctionable shock'resultsalso from isapproximately thezpitch linespeed of the die thesudden stopping offth'elworkpiecelanct the 40 grooves of'the rollslduring-rthelmajorl portion, of mandrel at the-end "ofzthe return stroke. Iiithe, thest-rokes inweach.directionrby segmentalgea i workpiece were'cold, these shockswould. cause. and, rack driving meansnand the deceleration, such--'rapid impairment .of the dies; anduinjury. reversal. and accelerationsbetween. strokes :is. cf,- to 'theworkpi'ece that use Of. Sl.ZCh Jlli11 S .fdIE.CO1d,. fect,ed ,by, crank.piniandif ll wenecamz mea reduction,woulribe'quiterimpractical'unless. the,. In a driving mechanism. ofztheforminow cone miu'were 1500 slfiwlyior practicalcommercial; sidered best ,and ,as. now. made, the segmental use." gear and rack means comprises ahorizontally To avoidiheseshocks. in the operation .ofiafl 4 reciprocating raok member with. teeth top and pileer mill, theworkpiece must beustartediinm bottom and two interrupted or segmental, gears motion at *the-"beginning"of "the workingnstroke "or pinions driven to movelthe reciprocatin r and its 'speed'brought'up to approximately the member in opp site directions, anti the.crank pitch line speed ofrthe die :grooves .of, the rolls p and follower-cam means compllses" 3 before the work-piece is engageclby the rol1s, and l head forming part of .or. otherwise connected its motion must be reversed without shock at the. to move with the reciprocating member and havend- 'oii each stroke. The Workpiece'and 'mandre1' "ing two spaced vertical open-ended calm slots or grooves and a coacting crank the axis of rotation of which extends at right angles to the direction of movement of the reciprocating member and the crank pin of which engages in the slots of the crosshead to effect harmonic motion reversal of the reciprocating member at the end of its movement at uniform velocity in each direction. The segmental gears are driven at the same R. P. M. as the die rolls. The crank pin has a radius twice that of the segmental gears and is driven at the same R. P. M. Therefore, when the crank pin is 30 from the horizontal, the horizontal component of the crank pin velocity is equal to the pitch velocity of the pinions. The slots of the crosshead are of such length and so positioned on the reciprocating member, and the crank shaft is so positioned with relation to the segmental pinions, that during the 60'movement of the crank pin from 30 above to 30 below the horizontal and during its 60 movement from 30 below to 30 above the horizontal, the crank pin will be moving in one of the slots and harmonic reversal of the movement of the reciprocating member will be effected by cooperation of the crank and crosshead. Reversal at each end of travel of the reciprocating member takes place during 60 of the cycle, or of the period of one revolution of the die rolls, and the reciprocating member is driven at uniform velocity in each direction during 120 of the cycle, or of the period of one revolution of the die rolls, the cycle being completed in 360. The crank pin is out of engagement with the crosshead except at and near the ends of travel of the reciprocating member.

The action of the mechanism is very smooth, there being no impact or inequality of motion when control of the movement of the reciprocating member is shifted from the pinions to the crank or from the crank to the pinions. The workpiece, and the mandrel in a tube mill, are given their reciprocating movements by the reciprocating member of the driving mechanism through suitable connections such that the movement at uniform velocity during 120 of each cycle will be at a speed approximately that of the pitch line of the grooves of the rolls, and, the grooves of the rolls extending over not more than 120 of the circumference of the rolls and the parts being properly timed, the operation of the mill is without harmful shock on engagement of the die rolls with the workp1ece or at the end of the strokes. Reversal of the reciprocating movements of the workpiece and mandrel and associated parts is effected without harmful shock -even in a comparatively heavy mill operating at comparatively high speed.

A full understanding of the invention can best be given by a detailed description in connection with drawings illustrating an embodiment of the invention in the form now considered best, and

such a description will now be given in connec tion with the accompanying drawings, in which:

Fig. 1 is a plan view of a tube reducing mill embodying the invention;

Fig. 2 is a side elevation of the mill;

Fig. 2a is a continuation of Fig. 2;

Fig. 3 is an enlarged sectional view of the new driving mechanism for reciprocating the tube and mandrel taken on line 3-3 of Fig.

Fig. 4 is a sectional view taken on line 3-4 of Fig. 3;

Fig. 5 is a sectional view on a larger scale taken on line 5--5 of Fig. 3;

Fig, 6 is an end view on a larger scale looking from the right of Fig. 3; and

Fig. 7 is a diagram illustrating the cycle of operations of the new driving mechanism.

The tube reducing mill shown by Figs. 1 and 2 of the drawings is a single mill similar in its principal operating parts other than its reciprocating driving mechanism to the duplex tube reducing mill for which I have filed an application for Patent Serial No. 442,769, filed May 13 1942. The present invention is in certain respects an improvement on the tube reducng mill of said application, the invention having been made especially with the idea of making it pos sible to operate a. comparatively large heavy powerful mill at comparatively high speed without loss of the desired smoothness of operation, and to obtain closer synchronization of speeds.

Referring to the drawings, and first to Figs. 1 and 2, the mill shown comprises a roll stand ID, a mandrel reciprocating and turning unit H, a tube reciprocating, turning and feeding unit 12, tube feeding mechanism l3, tube and mandrel reciprocating driving mechanism I4 and an exit tube reciprocating and turning unit !5.

The roll stand comprises a pair of overhung gapped working or die rolls 2!) fast on the ends of shafts journaled in a massive frame or housing 22. A pair of overhung stress-balancing rolls 24 (one of which shows in Fig. 1) of the same diameter as the die rolls are fast on the roll shafts at the opposite side of the housing from the die rolls, and there is an overhung backing 'roll 26 for each of the die rolls and for each of the stress-balancing rolls. At the entrance side of the housing there is a clamping device 21 which is open during operation of the mill and is closed to clamp the rear end of a partially reduced tube when the mill is stopped.

The operating parts of the mandrel reciprocating and turning unit H are mounted in a stationary housing 30 seated on the rear end of a longitudinally extending base 3|. These operating parts are driven by a transverse driving shaft 32 which is oscillated by the reciprocating mechanism M. A lever arm 33 fast on shaft 32 reciprocates the mandrel bar 40, which has at its forward end a tapered mandrel. The mandrel bar extends through and is detachably secured by means of a clamp 4| to a longitudinally reciprocable and axially rotatable sleeve 42 the forward end of which is rotatably connected to a sliding member 43 which is reciprocated by the arm 33 through a link 44.

A longitudinal rock shaft 50 which extends forward from one side of the mandrel unit housing 30 is oscillated by the drive shaft 32 through a bevel segment gear 52 on the drive shaft, meshing with a bevel pinion 53 on shaft 50.

The tube reciprocating, turning and feeding unit I2 comprises a housing mounted to slide on the base 3| between the position shown by full lines in Figs. 1 and 2 and that indicated by dotted lines in Fig. 2. The rear end of the tube T is detachably secured by a clamp 6| to the forward end of a longitudinally reciprocatable and axially rotatable sleeve 62 through which the mandrel bar extends. The rearward end of sleeve 62 is connected to a sliding member 63 which is connected by a link 64 to a leve arm 65 extending from a pivotally mounted hub 66. This hub carries also a bevel gear segment 01 which meshes with a bevel pinion 68 carried by a sleeve which is slidable on the shaft 50 and is splined thereto so as to be turned therewith, and

654seosoillatedaandtithes-sleeve 621andetheratuhe:-

secured-e, thereto-1-isereoiprocated. The: arm 65;

r ofathei-tubeunitend the arms-:33 ofsthe-mandrel unit :-have-. the; same angulammotion and, .are:of theesame effective radial- ;lengthz-and 'areredriveni in .unison,--so-tthat theetubeand .mandrel are given z- 1 equal? and -synchronous.reciprocations:

Duringfeach-non-r-workingiforward strokesofrthee tube ands-mandrel; the-.tube-unit housing fifl -is:-'

given a short forwardvfeedingrmovement lay-which:

the stuberis. given an. increment :of -feed 'withfireri 1 a;

lation sto-tthe mandrel-a1 This wstepg byestepgfoneward- ;feedingmft thel-tubeeunit gis elfectedtbw av pinion :10 driven; through .-.a oneeway "clutchrofe the :tube feedinamechanismi I 3, -from a shaft J I,

the spinion -meshing- Wit-h'T-fl raekv12;extending,.,2oe

backward from -.-the-.tube2unit housing; through :a guideopening; inthe .stationaryhousing-B fl of :themandrel-:Lmit.- This TPi-lliOH- and rack I serve a-alses: for giving a quick return movement to the-tubes unit; when; after, being;disconnectedzirom-a a 253' nearlmcompleted tube,;it is to lee-moved baok-s'forthe positioning, of -a new tube,'-- thea-pin-ion being; their disconnected efronr the onesway feeding; clutchand being ,driven byi'anmotorwl5swhioh rise.

under: push button; control; Theshatt "I I \is-os-t 3o:

cillatedi-by; the 'driveshaft. 32ethroughwaesegmentt gear 13 :onzthe -driveeshaft twhich-umeshes azJoevei-pinion- '14 on shaft (I:

As:.the r--reduced :portionsafa-ther.tuberadvaneee' beyond-ithewdie rolls-they are-engaged Joye: ti'onuclampifiilof the exittubereciprocating and turning unit] 5;" This friction clamp ,permits-slipgpage; under, the increment. of feed of vthenew tube during. each non-working stroke and:.vslippagei-+ duringgthe working; strokewduev :to the z-elon gatiom 4 of .thetube; The exit: tube: unit; I5 comprisesava: stationary housing: 8 I in which:- is rrmounted a. 3- longitudi-nallyyreciprocable and raxially rotatablee sleeve 82- which carries the: friction'iclamp t 80 and' which: is reciprocatedt, -in-;un-isom with-r. thesleeve-n62 f'ofzthe mainatubei unit 'by-,-means- Diwali oscillating leverarm 83 connected byya-linke84c toa'sliding jmBmbGY'BE'BOHHECtEd to-the sleeve flza The hubrof;'the:1everrarm;83l carries a bowel gear segmentxlidwhich meshes with'a-bevel pinion 814 fast on a shaft 88 which is connected withiands, osoillated by the rock-shaft .50. r

In the operation of-the= mill,-.aftereach work ing stroke I of-the tubexand mandreht duringewhioh aclengthlofthe tube-:is pressed betweene-workingdo portions of l the grooves :otethedie rolls;- the tube is zreleased by the "die: rolls and: ,the. tube. andmandrel then make a forward return stroke-dune M ing which they are givenra-rpartial turn andethe.

tube unit housing 604s moved forwardto -give-cof an-increment offeedto the -tube. When the. housing 68 has been advanced to itsextreme fora ward position, as shown by fulltlinest-in-Figsml and:.,2, the mill is: stopped. and -theeunreduced reareendzof Ithe'tubeu-isrclampedzzby the clamp-"65:

21; The sleeve 62 .vof the tube unit lis them dis-t connected from the tube and the. mandrel baris s disconnected from the s1eeveA2;-and the housingn -is-moved backward-.to itseextremevretracted1 position indicated byv'dotted linesin-Figl, 2,.-and.-.70 the mandrel; bar is drawn back; by suitable means ,s not: shown,..unti1 the forward rend .of :the man-e drel is. back-.of' the tube clampc oftthe retracted. tubezunit, A new tube -.may then .be brought intos fricv- 15 thee clan-m 6 I; and i-When-j the emandrel"; barehas; beenoreturned tot -operative position and-:4 can: neotedtmsleeve-AZ;;theemill may againzbe-started in operation. I

Thenmillasssofar:describedisrmore fully shown and ldescribedeinamysaidz application SeriaL N o. 442,769,+ with1- this =principa-l difference; however;

r thattheemili ofvsaid application is azlduplex mill whichsoperates on .:two I tubes at thesame-time; havingedie -:rol1s-on:each sidewof-.-the-:rol1- stand housing-instead. of die-rolls tom one .side rand stress balanoing-rollslon:the-otherside as-herein shown, andlhaving two-llongitudinalIro ck shafts like the shafit s'fleqoneeon'r each side Ofathe': base .3I; and: tuhes-andsmand-rel -gr-:ipping and-. operating parts om-zea-ohtsider z-of thewmandrel and tubew-unitsi The constructionsof sthe single mill: illustrated hereimis:obviouslyfisuchithat the designrcouldif I desired, tam-converted to alduplex-milL;

The". reciprocating,- driving mechanism l i -for oscillating the shaft :3 Z [by which :the mandrele reciproeating sleeve A2 land-the .tube-reciprocatinggsleeve .5 2:are;recipgocatedmomprises .arecip rocating member fi0+9I-=made--up;of' a rack mem-H ber =9B-.andaecrossheadyor follower :cam member, 9 Ian Thexracksmemberds mounted to .-slide-inl a housing-gSZanounted one-a base 93--andhas two racks S4 and 95 on opposite sides thereof. The crosshead-t memben 9 I- is lslidablyz mounted" one a sIideWay' QS' Onaa standefll mounted on the base- 93:11. The. memberfifle-QI is driven-during. the' maior-t part a of 'itsoreoiprocatingl movements in each direction :by-twosegmental: gears: or pinions, l otleand l l i. Pinion 1-I lJIL-engages-.-theupper rack fld-todr-i-vethe memberto the left inrFigss 3 :and 4; andepinion :I (it. engages thelower rack 95-to:drivethesmember to the right. The pinions are mountedefastson shafits ll 02 and-1ll3rw hich are journaled inz-bearings ,IIMna-nd. each oft-which is drivenrbythermain mill motor I (-through" a right angle v speed reducingqunittIGIi-Cand: a-gear stand. I01. This motor drives also the die rolls through-a right-- angle speedlreducing I 98-and through a .gean-stand- I OSfrQmFWhich-shafts I I0, one of: whioh.-shoWs-in,w-Fig. 1, extend-to the die roll shafts. Y. The; pinions ;-I We and- LI 0 I .-both-' rotate in the same direction, ands-are driven at; theasame' R: P.-; :M. as the: dierollsm Thergea-r segments 1 of,-=pin-ions -I Eli] and.- .I III are OfI-SllCh xangulainextent that.- each pinion-- by-en+ 1 beret is :maintained. ass-hereinafter:explained, and

ingr 6Qzof revolution-ofthetpinions, or ones-sixth ofna (cycleof operation; atthesendr of movement OfAmemherFSU-H-S i iinteach-rdirection."

AcrankA 253; the radial-length of which -is twice thetpitchl linetradiussofsthegear segments of" pinions, I fifisande I BI and" which is driven. at the samehR. P. -Meas pinions r I 00 and I 0 I cooperates withlthe crosshead 9I towdeceleratet reverse and accelerate, the movement ofemember --9 I during.,the..60 degrees of revolution when :the racks arecfree from.. the.-pinions.-- Theo-crank -;is fast on position in the' ;mill and its :rear-end secured bya'lb' cutsta lineiextending midway-betweenltheipinionsz the crosshead is so positioned with relation to the crank shaft I2 I, and the crank is so positioned an'gularly with relation to the segmental pinions,

that thecrank pin I25 engages vertical slot I22 when at 30 above the horizontal and after pinion I has ceased to exert moving force on member 90-9I by engagement with rack 94, and the crank then controls the movement of member 90--9I until, at 30 below the horizontal, the crank pin leaves the slot as pinion IIII comes into engagement with rack 95 On the backward stroke of member 909I; and after 120 rotation of the pinions and crank, the crank pin, when at 30 below the horizontal, engages vertical slot I23 after pinion I III has ceased to exert moving force on member 90-9I by engagement with rack 95, and the crank then controls the movement of member 909I until, at 30 above the horizontal, the crank pin leaves the slot as pinion I00 comes into engagement with rack 94 on the forward stroke;

As the horizontal harmonic motion of the crank pin at 30 from the horizontal either above or below is the same as the uniform motion of member 909I when driven by the pinions, there is no impact from inequality of motion when the crank pin engages and disengages the crosshead slots. Member 90-9I is thus driven at uniform velocity during one-third of the cycle in each direction and its motion is reversed with harmonic motion at each end of travel during one sixth of the cycle, and the transition from uniform speed to harmonic reversing motion is accomplished smoothly without shock and vice versa.

In order that the disengagement of the pinion teeth from the rack shall be without interference, the crosshead slots on their entrance ends are extended to serve as uniform velocity cams for maintaining the uniform speed of the reciprocating member during the time that the pinion teeth are getting clear from the rack teeth. If the pinion segments were made of a total length suflicient to maintain the uniform velocity drive of the reciprocating member during the whole 120 of revolution of the pinions, then when the crank pin took command of the movement of the reciprocating member and began immediately to slow it down there would necessarily be interference between the receding pinion teeth and the rack. To avoid this, the pinion segments are shortened at the recess end to an extent such that full speed drive of the reciprocating member by each pinion ceases at about 8 before the pinion has made a full 120 driving movement and before harmonic motion by the crank begins, and the crosshead slots have extensions at their entrance ends curved to serve as uniform velocity cams during the 8 A; intervals after the pinions have ceased to exert force on the reciprocating member and before the harmonic motion begins. It is not necessary, but for symmetry the slots are most desirably similarly extended at their leaving ends as shown.

The cycle of operations as above described is shown diagrammatically by Fig. 7.

For driving the oscillating driving shaft 32 by which the mandrel-reciprocating member and the tube-reciprocating-member are driVen the reciprocating member -9I is connected by a link I30 to a rocking lever arm I3I carried by a rock shaft I32 which is in line with shaft32 and is connected thereto by a sleeve coupling I33. The lever arm I3I is of such length according to the length of the reciprocating movements of the member 909I that the oscillations of shafts I32 and 32 will be of such angular extent that the mandreland tube-reciprocating members 42 and 62 will be given reciprocations of the desired length, that is, that on each working stroke and on each return stroke they will be moved at substantially uniform velocity approximately equal to the pitch line speed of the dies during of rotation of the die rolls and will be decelerated, reversed, and accelerated during 60 at each end of stroke. The timing adjustment of the segmental pinions I00 and. IN and crank I20 must, of course, be such that the mandrel bar and tube will be given their uniform velocity movement on the working stroke during the time that the dies are in engagement with the tube.

For changing the amplitude of the oscillations of shafts I 32 and 32, and thereby varying the length of stroke given to the tube and mandrel bar for operating the mill with die rolls of different diameters, provision is made for changing the effective radial length of the lever arm I3I.

For this purpose, the end of link I30 and the end of the lever arm have two or more, two as shown, sets of holes for the connecting pivot pin I34. By shifting the pivot pin from the upper holes in which it is shown to the lower holes I35, the effective length of the lever arm is reduced, and thereby a greater oscillation is given to the shafts I32 and 32. As in the mill of my said application Serial No. 442,769, the points of pivotal connection between the lever arms 33 and 65 and the links 44 and 64 of the mill shown by the drawings of this application are adjustable for varying the effective radial length of these lever arms. This provides for suflicient adjustment of the length of stroke of the tube and mandrel bar for operating with die rolls of a certain difference in diameter. Changing the pivotal connection between the link I30 and the lever arm I3I widens the range of adjustment, thus providing for the use of die rolls of greater difference in diameter.

The mill is most desirably, though not necessarily, provided with counterbalancing means for balancing the inertia effects of reciprocating parts at the ends of the strokes by cushioning the decelerating forces and absorbing energy during deceleration of the parts and returning energy to the reciprocating parts during acceleration. The counterbalancing means may be applied to different reciprocating parts of the mill, and counterbalancing means of different kinds may be used. In the mill shown, air-cylinder compensating means are used Most desirably, and as shown, the mill is provided with a pair of air cylinders I40 for counterbalancing the reciprocating member 909I, the rod I4I from the pistons of which is connected to the crosshead 9|, and with a pair of air cylinders I42 and I43 the piston rods I44 and I45 of which are connected by links I46 and I4! to short arms extending from the hub of the oscillating lever arm 33 of the mandrel unit II, and with a pair of air cylinders I50 and I5I the piston rods I52 and I53 of which are connected by 1inks I54 and I55 to short arms extending from the hub of the oscillating -lever arm- 83 of the-exit-tube I unit I 5.

The -tube-- a-nd-mandrel bar -steadying -devices It is -to-be understood that theinventionis not -limited-to the exact construction, arrangement and-combination of 1 parts shown-and towhich the foregoing description has-been---1argely COD.-

' fined,--but that it includes changes-anmm'ed-i-fica- I tionsthereof within the claims.

What is claimed is: 1.?In a pilgen millof the type -hav ing gapped die--rolls mounted to rotate -continuously one -di-rection-ahout fixed axes to work onsuccessive portions of a reciprocating workpiece =onsuccessive reci-procations, the improvement whichconsists in providing driving :mechanism -for -recip- --rocat-i-ng- *theworkpiececomprising a --rack- -member; -tw0-- segmental gears for driving: 1 the--rack member in opposite-directions at uniformspeed during a mag or portion of-its--reciprocating-move :ment- "in each direction; a transverselyslotted crosshead connected to-move with the rack-memher; a; crank for cooperating--with-= the crosshead to reversethemovement oft-he rack-member-and crosshead-w-hen the rack member is free from the segmental gears at each end of movement.

' .2. In apilger mill of the type-having-gapped dierollsmounted to rotate continuously inone direction aboutfixed axes to Work on successive portions of a reciprocating workpieceonsuccessive reciprocations, the improvement-whichconsists in providing driving mechanism for reciprocating the workpiece comprising a rack-member, twosegmental gears driven atthe same R; P: as the die rolls ,for driving the rack member in oppositeadirections at uniform velocity during amajor portion of its reciprocating movement in eachdirection, a crossheadconnected to move withjthe rack member having two spaced cam slots extending at right angles to-the direction of movement. of the crosshead and rack member, and a crank for cooperating with the crosshead to reverse the movements of the rack member during 60 of revolution when ltliS free tromthe segmental gears at each end of movement; the crank having a length equal to twice the pitch line radius ofthe segmental'gears and being driven at'the sameR. P; M. as the segmental gears, and the camslots of the crosshead being of such length and so positioned and'the crank shaft being so positioned, with relation to the segmental gears that the crank pin will move'through eachof the slots during itsmovement from 30, on one sideof a line extending through the axis .of rotation of the crankto; 30H0n the othervsicle of .said line, and each of the slots having an extension at its entrance end curved to serve as a uniform velocity cam for maintaining the uniform speed, of, the rack member for a brief, intervalwhile the segmental gear which has been driving the rackmember clears from the rack, whereby, the.workpi ece is driven in each direction at approximately, the pitch line speedof the grooves of the die rollsduringone-third of the cycle andiits movementis reversed. with symmetrical deceleration and acceleration during one-sixth ofthe cycle at, each end of movement.

.3. Inca pilger mill of the type having gapped die vrolls ,Y mounted to. rotate continuously in .one

direction about fixed, axes. to Work, on successive portions of a reciprocating workpiece on succes- '45- angles to the;

therackmemberhaving two spaced straight 10- --cam slots; extending at right angles to the direc- '-t-ion-of;n1ovement ofthe crosshead and rack member, and acrank for-;cooperatingwith the crosswhead to reverse'the movements of the rack memduringiiOi- Off revolution whenjt is iree'irom --t-he segmental gears at each end of movement, -tl- 1e-crank-having a-length equal to twice'the pitch -'--1ineradius of the segmental gears and being driven-;at-the same *RrP: as the segmental --gears; and the cam slots of the crosshead bein of--such length and so positionedand the crank ;--shaftbeing so; positioned with relation tothe segmental gears that jthQ crank pin will move through each of the slots; during its movement atom 1 esid oial ne ex end n o h the axisofrotation of the crank to on the o e i a i hez e saqh 0 eslo hav- 1 ing an extension at its entrance end curved to serve uni r YQ OQit CQmiIfQ maintai in the iiniform'speecl oi-the rackmember for a brief intervalwhilethe segmental gearwh ich haslrbeen driving the rack rnernber clears from theira ck, -w-here by-the workpiece is 'driv in each direction atapproximately the V pitch me speed oifthe --groovesof the die rolls d ring one-third of the 5 cycle and;its movemcntjs reversed withvsvm- -m-etrical: decelerationnnd acceleration during one sixth pf thecycleat each end oim ovement."

4o s kp e e. .r q prg at e. me be ah cre- -s h imeq ahism"fo ,dr viher a hmemh r i ch i m co p isin n ehdwis mem member includinga rack portion and a .crosshead -havmg two spaced 'camslots extending at right .h u teq p voim reme tof saidjmemg r w ss me tam iyih sear fo len n l h rack portion otsaid member to move said member j n'opposite directions at uniform velocity during its reciprocating movement -the major; portion, of y 60 in m ifi tiqnra ra whi h. by, enga men deqel re e -,re ers -an the; s egmentahgears at -and"means for driving he segmental gears and 3-1 sth fl e rolls,

he ank at esa ne ;t-he-crank being pf; avg-length equal to twice the tc as i esoirt i hseem t l ears. andthe can; s ys: 9 th cr s eedrbe hs f s length Q; Fas ned fib33allk ha t b in [so sib sdrw thi r latio t t e s ment gears t t t r en ri rW l m ve hr u h a h' f the q rfiur h z smovem n .ir m 3 79 1 Side "O n s-exteh ii .throughuth t m n rot t rtheqnh ro..s iph he oth hside r Said l 3 5,1 atube re uc ezwhi g r. r n com i t iqnra na higaarped ld e .r l s e n d to r a abou fixe ce se a tu e-reci roca ing.m mber, a; mandrel-reciprocating member, and reciproi =1315393 19 1i lld fivil fi id m a d mech anism omprising an endvvise movable memb .t. hq i l xt ia.tfrankv pert io a d a rvo se d, y ih x w gspa ed;fi slq i. tehti h a ri h an le plth 'ld r et on of moveme fi said member, two segmental driving gears for engaging the rack portion of said member to move said member in opposite directions at uniform velocity during the major portion of its reciprocating movement in each direction, a

crank which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said member during 60 of revolution when said member is free from the segmental gears at each end of movement, and means for driving the segmental gears and the crank at the same R. P. M. as the die rolls, the crank being of a length equal to twice the pitch line radius of the segmental gears, and the cam slots of the crosshead being of such length and so positioned and the crank shaft being so positioned with relation to the segmental gears that the crank pin will move through each of the slots during its movement from 30 on one side of a line extending-through the axis of rotation of the crank to 30 on the other side of said line.

6. In a pilger mill, in combination, a pair of gapped die rolls mounted to rotate about fixed axes, a workpiece reciprocating member, and reciprocating mechanism for driving said member, said mechanism comprising an endwise movable member including a rack portion and a crosshead having two spaced cam slots extending at right angles to the direction of movement of said member, two segmental driving gears for engaging the rack portion of said member to move said member in opposite directions at uniform velocity during the major portion of its reciprocating movement in each direction, a crank which by engagement with the crossheadslots decelerates, reverses and accelerates the movement of said member during 60 of revolution when said member is free from the segmental gears at each end of movement, and means for driving the segmental gears and the crank at the same R. P. M. as the die rolls, the crank being of a length equal to twice the pitch line radius of the segmental gears, and the cam slots of the crosshead being of Such length and so positioned and the crank shaft being so positioned with relation to the segmental gears that the crank pin will move through each of the slots during its movement. from 30 on one side of the line extending through the axis of rotation of the crank to 30 on the other side of said line, and each of the cam slots having an extension at its entrance end curved to serve as a uniform velocity cam for maintaining by co-- operation with the crank pin auniform speed of movement of said member for a brief interval while the segmental gear which has been driving said'member clears from the rack.

'7. Reciprocating mechanism, comprising an endwise movable rack member, two segmental gears engaging the rack member to move itjin opposite directions during a major portion of its reciprocating movement in each direction, a transversely slotted crosshead connected to move with the rack member, a crank the length of which is equal to twice the pitch line radius of the segmental gears and which cooperates with the slotted crosshead to decelerate, reverse and accelerate the movement of the rack member when it is free from the segmental gears at each end of movement, and'means for driving the segmental gears and the crank at the same R. P, M.

8. Reciprocating mechanism, comprising an endwise movable member, two racks on said member, two segmental driving gears ior engaging said racks to move said member in opposite directions during a major portion of its reciprocating movement in each direction, a

crosshead on said member having two spaced cam slots extending at right angles to the direction of movement of said member, a crank the length of which is equal to twice the pitch line radiusof thesegmental gears and which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said member at each end of movement, and means for driving the segmental gears and the crank at the same R. P. M.

9. Reciprocating mechanism, comprising an endwise movable member, two racks on said member, two segmental driving gears for engaging said racks to move said member in opposite directions during a major portion of its reciprocating movement in each direction, a crosshead on said member having two spaced cam slots extending at right angles to the direction of movement of said member, a crank the length of which is equal to twice the pitch line radius of the segmental gears and which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said member at each end of movement, means for driving the segmental gears and the crank at the same R. P, M.,

and counterbalancing means for absorbing energy from said member during deceleration and for returning energy thereto during acceleration thereof.

10. Reciprocating mechanism, comprisingan endwise movable member, two racks on opposite sides of said member, 'two segmental driving gears for engaging said racks to move said member in opposite directions during a majo portion of its reciprocating movement in each direction, a crosshead on said member having two spaced straight cam slots extending at right angles to the direction of movement of said member, a crank the length of which is equal to twice the pitch line radius of the segmental gears and. which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said meniber'when it is free from the segmental gears at each end of movement, and means for driving the segmental gears and the crank at the same R. P. M.

11. Reciprocating mechanism, comprising an endwise movable member including a rack portion and a crosshead having two spaced cam slots extending at right angles to the direction of movement of said member, two segmental driving gears engaging the rack portion of said member to move said member in opposite directions at uniform velocity during a major portion of its reciprocating movement in each direction, a crank which by engagement with the crosshead slots decelerates, reverses and acceleratesthe movement of said member during 60 of revolution when said member is free from the segmental gears at eachend of movement, and means for driving the segmental gears and the crank at the same R. P. M., the crank being of a length equal to twice the pitch line radius of the segmental gears, and the cam slots of the crosshead being of such length and so positioned and the crank shaft being so positioned with relation to the segmental gears that the crank pin will move through each of the slots during its movement from 30 on one side of a line extending through the axis of rotation of the crank to 30 on the other side of said line.

12. Reciprocating mechanism, comprising an endwise movable member including a rack portion and a crosshead having two spaced cam slots extending at right angles to the direction of movement of said member, two segmental driving gears for engaging the rack portion of said member to move said member in opposite directions at uniform velocity during a majo portion of its reciprocating movement in each direction, a crank which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said member during 60 of revolution when said member is free from the segmental gears at each end of movement, and means for driving the segmental gears and crank at the same R. P. M., the crank being of a length equal to twice the pitch line radius of the segmental gears, and. the cam slots of the crosshead being of such length and so positioned and the crank shaft being so positioned with relation to the segmental gears that the crank pin will move through each of the slots during its movement from 30 on one side of a line extending through the axis of rotation of the crank to 30 on the other side of said line, and each of the cam slots having an extension at its entrance end curved to serve as a uniform velocity cam for maintaining by cooperation with the crank pin the uniform speed of movement of said member for a brief interval while the segmental posite directions at uniform speed during a major I portion of its reciprocating movement in each direction, a crank the length of which is equal to twice the pitch line radius of the segmental gears and which by engagement with the crosshead slots decelerates, reverses and accelerates the movement of said member, means for driving the segmental gears and the crank at the same R. P. M., and counterbalancing means for absorbing energy from said member during deceleration and fo returning energy thereto during acceleration thereof.

HEBER C. INSLEE. 

